Fixing Cracks in a Backhoe - Big ! with pics

[sandman2234]

I really like 7014 rods, when I can use them. They make me look like I might know what I am doing, dispite the truth of the matter! Wish they made them for all positions and AC/DC to cover a few more passes...
David from jax

 

[3RRL]

...
Does ANYONE chip off the slag???? Once the slag has been chipped, the newly exposed welds are seen to be of extremely poor quality. The slag isn't just jumping off and I am only able to get it off with a chisel. So, have ordered a needle scaler from HF to help get this stuff off. ...
jb

Hi John,
I got one those needle scalers and it works pretty good. I found that you still want to go into some corners with the chipping hammer to get the stuff it missed. Another easy way is to use a wire wheel on an angle grinder. I find that works best to those areas you can get to. Gets the slag of really good and clean. I also use it to prep...remove paint and rust for areas I'm going to weld.

 

[Egon]

Is it possible to use the angle grinder and grind out slag areas?

 

[john_bud]

Hi John,
I got one those needle scalers and it works pretty good. I found that you still want to go into some corners with the chipping hammer to get the stuff it missed. Another easy way is to use a wire wheel on an angle grinder. I find that works best to those areas you can get to. Gets the slag of really good and clean. I also use it to prep...remove paint and rust for areas I'm going to weld.

3RRL,

I do use a wire brush in my angle grinders. I have multiple brushes, 3", 4", 5" cups in Extra Course along with the flat disc brushes in 3" and 4". I've worn out at least 6 of them on the backhoe and tractor. I am not sure what the rod was that was used, but at a guess 6011 or 6013. It has very tenacious slag that does not want to come off. The rust all came off and leaves the slag behind. I have been using a chisel and 24 oz ball peen hammer, old punch and hammer and chipping hammer. I often still have to grind it off with a disc! This last week I went thru 5 of the 4 1/2" x 1/4" disc's and 6 of the 4 1/2 x 1/8" cutting discs.

Let me tell you, it gets old kneeling on the cold concrete, bent over with your head and shoulders inside the bucket chiseling off slag. Then using the wire brush and getting smacked in the face, neck, chest, arms and hands by loose pieces of slag, rust, dirt and wires from the brushes. Don't even get me started on the cloud of dust that fills the shop from all the grinding and brushing. Nothing brings on a round of muttering like grinding off nasty old weld and have the sparks replaced by dust when you hit slag! I'll let you know how I like the scaler, it's scheduled for delivery on the 18th.


Oh well! It should be decent when done, even if it looks like my name is Dr. Frankenstein! For giggles, I checked out what a new 10' hoe would cost. (JD 49 $11,000 - hoe only). That helps me justify the time and expense. On paper, the new JD 310G has about the same specs as the hoe I'm working on. That's probably why it's so broke up! The JD is about 2x the metal!

 

[3RRL]

John,
I hear you about it getting old under less than perfect working conditions. I know exactly what you're talking about. I admire your tenacity that being a large project presenting problems in it's own... let alone the annoying circumstances of the old slag on top of it. Murphy must have been one **** of a guy!

I also agree with you on the re-build. I guess I'm school and if you can get it to work properly with a little time and elbow grease, it sure beats the dent in the old savings fund by a long shot. Especially if you are not using the equipment for commercial use where a new purchase can be written off and expenses easily recovered from trouble free work that you're getting paid for.

Keep at it, you almost got it all now. We're all pulling for you.
Thanks for sharing your project.

 

[john_bud]

Rob, Thanks for the kind words.


No work on the hoe today. We were blessed with 5" of white fluff this morning and school is closed. Been having fun snowblowing up a big snow pile for my son. Took some doing as this is light fluffy snow. Had to blow the driveway snow down and the side yard over just to get a 3' tall mound.

First sign of white on the ground since November. Those selfish guys out west have been hogging it all!

I did get some possible good news. Neighbor may have some Hensley bolt on teeth from a LARGE excavator that he may let me have. Sounds like they may be a bit on the overkill side, size wise, but just about perfect on the price scale. He's checking around his shop for them. That would be just too cool!

Well, gotta go out and see how the sledding hill is.

jb

 

[thingy]

Carbon arc gouging is used sometimes to do what you are doing John,,,I've used it,but its been a long time,,but they use it sometimes in powerplants to cut out old welds,,,I've only been around it using a stick machine,using dc electode postive,but they may have rods that can be used on ac.
You have this rod holder,thats got a connection for air and a block to hook up your stinger,,,,the rod holder has a little button that lets air out a couple little holes that blows out the melted steel your carbon rod makes,,,kinda like oxy/acetylene cutting,but made to blow out melted steel better.
Works good for cutting out a weld or gouging out a groove. Uses a good bit of amps though,,,not sure how many,,but you can only get the rod down to about 5/32 I think,good bit of air pressure to,,,,makes a **** of a noise,and sparks fly every where,,,,,,but you could probably make a foot long big ugly fillit weld disapear in 3-4 min,,not hard to use either,,,thingy

 

[tlbuser]

Let me tell you, it gets old kneeling on the cold concrete, bent over with your head and shoulders inside the bucket chiseling off slag. Then using the wire brush and getting smacked in the face, neck, chest, arms and hands by loose pieces of slag, rust, dirt and wires from the brushes. Don't even get me started on the cloud of dust that fills the shop from all the grinding and brushing. Nothing brings on a round of muttering like grinding off nasty old weld and have the sparks replaced by dust when you hit slag!

Just think of all the fun and experience you're gaining and what a great "new" machine you're going to have in the long run. It'll be worth it and the memories and pic's. will last more than your lifetime.

 

[PBinWA]

Carbon arc gouging is used sometimes to do what you are doing John,,,I've used it,but its been a long time,,but they use it sometimes in powerplants to cut out old welds,,,I've only been around it using a stick machine,using dc electode postive,but they may have rods that can be used on ac.
You have this rod holder,thats got a connection for air and a block to hook up your stinger,,,,the rod holder has a little button that lets air out a couple little holes that blows out the melted steel your carbon rod makes,,,kinda like oxy/acetylene cutting,but made to blow out melted steel better.
Works good for cutting out a weld or gouging out a groove. Uses a good bit of amps though,,,not sure how many,,but you can only get the rod down to about 5/32 I think,good bit of air pressure to,,,,makes a **** of a noise,and sparks fly every where,,,,,,but you could probably make a foot long big ugly fillit weld disapear in 3-4 min,,not hard to use either,,,thingy

What about a gouging/scarfing tip for a torch?

Welcome to GENSTAR TECHNOLOGIES COMPANY

Might be useful for a break from the grinder.

 

[john_bud]

Hmm, May have to look into that scarfing.

I ground out some disreputable welds on the back / bottom of the bucket where the liner is attached. I was certain it was solid metal. I ground it around the ugly spots, chipped off slag, ground out slag. Then I welded the parts that were ground. Then kept going an additional 8" or so to the edge of the bucket as it was looking a bit "thin". As I left the area that I had ground, it started to sound a bit different. Sort of softer, if you can follow that. Initially, I thought the gas was going out, but no. Then I double checked the settings on the welder - all good. Well, when I looked at the part I had just welded, a curse did leave my lips. The weld was covered with slag! Not just a bit or a scrap, but the whole dang dern darn thing was covered with stinking slag! I chipped it off.

I looked at the other side of the part I had ground. I had hit it with a wire brush pretty hard to get rid of all the rust, dirt etc. I mean I leaned into it with a 5" extra course wire brush on a Milwaukee grinder until the grinder got too hot to hold. I got a chisel and gave the "weld" a whack with a 24 oz ball peen hammer. ZING! off flys a chunk of slag. Jeeze!

Oh well, on the bright side, I now have some experience with flux MIG welding. Who would have thought that the welder would melt it down and have it weld about normally?

Yeah yeah, I'll grind it out and do it over! Mutter mutter grumble

jb